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Netlab Reference Manual demgpot
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<H1> demgpot
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<h2>
Purpose
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Computes the gradient of the negative log likelihood for a mixture model.

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Synopsis
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<PRE>
g = demgpot(x, mix)</PRE>


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Description
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This function computes the gradient of the negative log of the unconditional data
density <CODE>p(x)</CODE> with respect to the coefficients of the
data vector <CODE>x</CODE> for a Gaussian mixture model.  The data structure
<CODE>mix</CODE> defines the mixture model, while the matrix <CODE>x</CODE> contains
the data vector as a row vector. Note the unusual order of the arguments:
this is so that the function can be used in <CODE>demhmc1</CODE> directly for
sampling from the distribution <CODE>p(x)</CODE>.

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See Also
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<CODE><a href="demhmc1.htm">demhmc1</a></CODE>, <CODE><a href="demmet1.htm">demmet1</a></CODE>, <CODE><a href="dempot.htm">dempot</a></CODE><hr>
<b>Pages:</b>
<a href="index.htm">Index</a>
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<p>Copyright (c) Ian T Nabney (1996-9)


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